Articulating Versus Static Antibiotic Loaded Spacers for the Treatment of Prosthetic Knee Infection

Summary

Infection remains a difficult-to-treat complication of total knee arthroplasty. The gold standard treatment is two-stage removal of the prosthesis with later replacement of permanent implants. The first stage consists of removal of the infected arthroplasty components and the surrounding devitalized tissue, copious pulsed irrigation, and placement of a temporary antibiotic-impregnated cement spacer. This spacer typically is left in place six weeks, during which time the patient receives intravenous antibiotics. After the surgeon feels that the infection has been eradicated, or if the patient requires repeat debridement, a second operative procedure is performed. While the use of an antibiotic-loaded spacer is well accepted, whether the spacer should immobilize the knee (a so-called "static" spacer) or allow for range of motion (a so-called "articulating" spacer) is controversial. Proponents of articulating spacers argue that they prevent scarring of the musculature surrounding the knee resulting in easier reimplantation, improved long-term knee function, and improved range of motion. Proponents of static spacers argue that immobilization of the periarticular soft tissues aids in clearance of the infection and is simpler to fashion intraoperatively. While good results have been described with both methods, comparative trials have been conflicting as to whether spacer design alters knee function, operative time, and range of motion. Equipoise exists within the literature, and no randomized clinical trial has been conducted to evaluate this issue.

The purpose of this study is to compare articulating and static antibiotic-impregnated spacers for the treatment of chronic periprosthetic infection complicating total knee arthroplasty through a prospective, randomized clinical trial. The goals of this trial are to determine the effect of spacer design upon eradication of infection, knee function, ease of reimplantation, and range of motion. The investigators hypothesize that articulating spacers will provide shorter operative times at reimplantation, while improving knee function and range of motion.

Conditions

• Osteoarthritis
• Knee Infection
• Prosthetic Joint Infection
• Complications; Arthroplasty, Infection or Inflammation
• Complications; Arthroplasty

Interventions

PROCEDURE

Static Spacer

After diagnosis of infection and informed consent, patients will be taken to the operating room. After anesthetization, patients will be randomized to either an articulating spacer or a static spacer. Randomization will be performed by prepared opaque envelopes administered by a nonparticipant in the study. After a complete debridement of devitalized tissue, explantation of the infected components and any associated cement, either an articulating or static spacer will be placed. All spacers will be formed of 3 g of Vancomycin and 1 g of Tobramycin for each 40 g packet of cement. Static spacers will be hand-made to fit the femoral and tibial exposed metaphyses as a solid block with associated antibiotic cement coated tibial and femoral intramedullary rod, such that knee motion will be minimized.

PROCEDURE

Articulating Spacer

After diagnosis of infection and informed consent, patients will be taken to the operating room. After anesthetization, patients will be randomized to either an articulating spacer or a static spacer. Randomization will be performed by prepared opaque envelopes administered by a nonparticipant in the study. After a complete debridement of devitalized tissue, explantation of the infected components and any associated cement, either an articulating or static spacer will be placed. All spacers will be formed of 3 g of Vancomycin and 1 g of Tobramycin for each 40 g packet of cement. Articulating spacers will be formed of antibiotic impregnated cement using the Stage One system (Biomet, Warsaw, IN).

Sponsors & Collaborators

• Central DuPage Hospital

  collaborator OTHER

• Joint Implant Surgeons, Inc.

  collaborator OTHER

• Thomas Jefferson University

  collaborator OTHER

• Rush University Medical Center

  lead OTHER

Principal Investigators

• Peter Chalmers, MD · Rush University Medical Center

• Craig Della Valle, MD · Rush University Medical Center

• Scott Sporer, MD · Rush University Medical Center

• Adolph Lombardi, MD · Joint Implant Surgeons, Inc.

• Keith Berend, MD · Joint Implant Surgeons, Inc.

• Matt Austin, MD · Thomas Jefferson Hospital

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

100 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2011-12-31

Primary Completion

2020-08-31

Completion

2020-08-31

Countries

• United States

Study Locations